U. S. DEPARTMENT OF AGRICULTURE. 
BUREAU OF PLANT INDUSTRY-BULLETIN No. 61. 

B.T. GALLOWAY, Chirf of Bureati. 



THE AVOCADO IN FLORIDA; 

ITS PROPAGATION, (TLTIVATION, AND MAMETING. 

BY 

P. H. ROLFS, 
Pathologist, in Charge of Subtropical Laboratory. 



POMOLOOICAL INVESTIGATIONS. 



l oSUKD July 7, 1904. 




WASHINGTON: 
goyerinment printing office. 
1904. 



Gass ^dd J4^ 



1 



Bui. 61 . Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 




U. S. DEPARTMENT OF AGRICULTURE, 
BUREAU OF PLANT INDUSTRY-BULLETIN No. 61. 

B. T. GALLOWAY, C/iltf oj Bureau. 



THE AVOCADO IN FLORIDA; 

ITS PROPAGATION, CULTIVATION, AND MARKETING. 

BY 

P5^f ROLFS, 
Pathologist, in Charge of Subtropical Laboratory. 



POMOLOOICAL INVESTIOATIONS. 



Issued July 7, 1904. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE, 

19 04. 

<^ ' ■ 



§ © 3 7 y 



BUKEAU OF PLANT INDUSTRY. 

Beverly T. Galloway, Cldef. 
J. E. EocKWELL, Editor. 

POMOLOGICAL INVESTIGATIONS. 
Scientific Staff. 
G. B. Brackett, Pomolor/ist. 

William A. Taylor, Pomologist in Charge of Field Investigations. 

G. Harold Powell, Pomologist in Charge of Fruit Storage Investigations. 

H. P. Gould, Assistant Pomologist in Charge of Fruit District Investigations. 
Sanford H. Fulton, Assistant Pomologist in Charge of Fruit Storage Investigations. 
George C. Husmann, Viticulturist. 



JAN 8 1907 
0.ofO. 



LETTER OF TRANSMimi. 



U. S. Department of Agriculture, 

Bureau of Plant Industry, 

Office of the Chief, 
Washington, D. April 7,1901^, 
Sir: I have the honor to transmit herewith a paper on "The Avocado 
in Florida; its Propagation, Cultivation, and Marketing," and respect- 
fully recommend that it be published as Bulletin No. 61 of the series 
of the Bureau. 

This paper was prepared by Prof. P. H. Rolfs, Pathologist in 
Charge of the Subtropical Laboratory at Miami, Fla., under the direc- 
tion of Dr. A. F. Woods, Pathologist of this Bureau, "but as the 
subject is pomological rather than pathological, it was submitted to 
the Pomologist with a view to its publication from his office. 

The accompanying illustrations are essential to an intelligent under- 
standing of the text. 

Respectfully, B. T. Galloway, 

Chief f Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 



3 



PREFACE. 



The avocado {Persea gmtissim,a) is one of the most recent fruits 
to receive intelligent and systematic treatment from American fruit 
growers. Though long held in high regard by persons livdng in 
southern Florida, the West Indies, and most portions of tropical 
America, it has not until recently attracted the attention of northern 
consumers, and is, in fact, at this time an interesting novelty rather 
than a recognized staple of commerce. This is probably due to the 
fact that it lacks those characteristics of texture and flav^or which 
are sought for in most dessert fruits, so that a taste for it must be 
acquired by most persons. In recent years, however, its usefulness 
as a salad fruit has gradually been recognized, so that a growing appre- 
ciation of its value in this regard has led to an increasing demand for 
it in our larger cities. 

Until very recently the principal supply for these markets has come 
from the West Indies, chiefly because of cheaper transportation from 
those islands than from Florida. The recent extension of railroad 
facilities to far southern Florida has made possible the safe shipment of 
this fruit from that section to practically all parts of the countr}^ and 
interest in its commercial culture there has therefore largeh^ increased. 

As it provides a wholesome and nutritious food, which, judging 
from present demand and prices, will afi'ord a profitable crop in loca- 
tions suitable to its pi'od action, its culture on a commercial scale 
appears worthy of encouragement in Porto Rico, southern Florida, 
Haw^aii, and such locations in California as are practically free from 
frost during the blossoming season. 

The greatest need at present appears to be the propagation of pro- 
ductive varieties of desirable size, form, and quality, ripening at an 
opportune time — that is, late in autumn or early in winter, when the 
demand in northern markets at high prices appears to be best. As the 
bud propagation of this fruit in a commercial way has but recently 
commenced, it is believed that this publication, which deals largely 
with that subject, will be of distinct value to those who desire to engage 
in its production. 

G. B. Brackett, 

Pomologist. 

Office of the Pomologist, 

Washington, D. C, March 29, WOJf,. 

5 



CONTENTS. 



Page 



Introduction 9 

The name avocado 10 

Literature 11 

Distribution and time of blooming 13 

The avocado for wind-breaks and shade trees 15 

Methods of starting an orchard 15 

The seed bed 16 

The nursery 16 

Cultivation in the nursery 17 

Budding 17 

Grafting 18 

Transplanting to the field 19 

Top- working trees 19 

Cultivation ' 20 

Fertilizers 20 

Superiority of budded trees 21 

Variation of fruit from seedling trees 21 

Description of variations 22 

Marketing 23 

Picking 23 

Grading and sizing 24 

Packing 25 

The fruit 27 

The edible portion 27 

Seed and seed cavity 28 

Shape of the tree 28 

Forms and varieties 28 

The Mexican avocado 29 

The West Indian-South American avocado 30 

The ideal avocado 31 

Uses of the fruit 31 

Diseases 32 

Leaf disease 32 

Remedy 32 

Fruit disease 33 

Pvemedy 33 

Summary 33 

Description of plates 36 



7 



ILLUSTRATIONS. 

PLATES. 

Page. 

Plate I. West Indian-South American avocado tree, thirty-five years old, 



II. Fig. 1. — Crown-worked West Indian-South American avocado tree, 
eighteen months after insertion of bud. Fig. 2. — Top-worked 
Mexican avocado tree, eighteen montlis after insertion of bud 36 

III. West Indian-South American avocado tree in nursery, transplanted 

from seed bed; 2 years old, 4 feet tall 36 

IV. Fruiting branch of West Indian-South American avocado tree, one- 

tenth natural diameter 36 

TEXT FIGURES. 

Fig. 1. Seedling avocado in December from seed planted in September 16 

2. Shield bud cut out preparatory to insertion 18 

3. Seedling avocado stock with shield bud inserted 18 

4. Shield bud wrapped with waxed cloth 18 

5. Bud stick. "Live" buds in various stages of development {a, a, etc. ). 

Blind buds which should not be used (h, h, etc.) 18 

6. Longitudinal sections of round avocados, West Indian-South American 

varieties: A, seed filling the cavity; B, fruit from another tree of 
better quality, but seed loose in the cavity 24 

7. Longitudinal sections of oblong avocados, West Indian-South Ameri- 

can varieties: A, small seed, loose in large cavity; B, large seed, loose 
in the cavity 24 

8. Longitudinal sections of pear-shaped avocados, West Indian-South 

American varieties: A, very large seed, loose in the cavity; B, large 
seed, loose in the cavity 25 

9. Longitudinal sections of bottle-necked avocados: A, West Indian- 

South American variety, with very large cavity; B, Mexican variety, 
with seed filling cavity • 26 

8 



B. P. I.— 100. 



Pom. I.— 24. 



THE AVOCADO IN FLORIDA; ITS PROPAGATION, CULTIVATION, 
. AND MARKETING. 



INTRODUCTION. 

The avocado {Persea grafJssima Gartn.) might almost he called a 
new fruit, for, while it has long been used as a food by the American 
aborigines, it has never been subjected to cultivation and careful 
breeding. Its value as a food is rapidly becoming known, and it is 
apparently only a question of time until it will be used extensivel}^ 
Its shipping qualities permit it to be sent to all the large consuming- 
centers of the United States, while its food value will make it a favorite 
with all lovers of good salad fruits. These pages have been prepared 
with a view to systematizing our knowledg'e of the avocado, and to 
point out the directions for its improvement. 

South Florida seems to be the only region in which the propagation 
of the avocado has been undertaken in a systematic way and on an 
extensive scale. Nurseries in that section have thousands of seedlings 
growing and hundreds of budded trees to put on the market. In 
addition to this, it seems to be the onh^ region where budded trees 
have fruited. 

The Pollock avocado, grown in South Florida, was exhibited at the 
meeting of the American Pomological Society in September, 1903. 
The original tree bears fruit of large size, the largest having approxi- 
mated 3 pounds in weight. The Trapp avocado, also grown in South 
Florida, is noteworthy in that it matures late, holding some of its 
fruit until January. 

The essential work of selecting and breeding varieties that are espe- 
cially adapted to certain sections and that are wanted b}^ the most 
desirable markets can now be pushed forward. 

The fact that it can now be definitely stated that seedlings do not 
come true to seed and that propagation by budding is possible marks 
a distinct epoch in the progress of growing this fruit. Another dis- 
tinct advance in the development of this salad fruit is that seedless 
fruit has been grown by the writer. 

The selling price of avocados varies considerably, the latest ripening- 
ones bringing much the best prices in American markets. Extremely 

9 



10 



THE AVOCADO IN FLORIDA. 



late ones have brought as high as |3 a dozen when shipped in lots of 
several crates at a time. This price gives the grower $6 to f 8 net per 
crate at the shipping station. The price for good fruit in sound condi- 
tion has never fallen so low as to make it unprofitable to ship it to 
markets that use it. In man}^ large cities in the United States the 
avocado can not be found at all, and as the dealers in Boston, New 
York, Washington, and New Orleans have been able to handle all the 
good fruit that has been sent to them, it is not probable that the 
avocado will be introduced into other centers until these markets have 
been full}^ supplied. 

THE NAME AVOCADO. 

This fruit has been called by various names — avocado, avocado pear, 
avocate, aguacate, alligator pear, midshipman's butter, etc. As early 
as 1696 Hans Sloane speaks of the "avocado or allegator pear-tree" 
and catalogues about a dozen other names by which it is known in 
literature. Previous to this date the avocado was known from "Nica- 
raguae and other portions of the American continent." 

Murray's New English Dictionary prefers the name avocado and 
gives the following reference: 

Taylor .■l??a/n?ac IX, 227 (1861). This is a well-known West Indian fruit which 
we call an avocado or alligator pear, and which the Fren(;h call " avocat" and the 
' Spanish " aguacate." All these names are the corruption of the Aztec name of the 
fruit "ahuacatl." 

Meissner ^ gives the following names as being used in various parts 
of America: 

In Peru, Palto and Aguacate; in Central America, Aguacate de Anis;.in Mexico, 
Aguacate; in Brazil, Avocate; in Antigua and British Guiana, Avocado Pear and 
Alligator Pear; in French Guiana, Laurier Avocat. 

The Florida State Horticultural Societ}"^ prefers the name avocado, 
while the American Pomological Society gives preference to "aguacate 
and uses avocado as second choice. When the Catalogue of Fruits shall 
be again revised, avocado will doubtless be given preference. 

According to the Century Dictionary, avocado is a corruption from 
the Mexican. The addition of the word pear, while describing the 
shape of the fruit in some varieties, is otherwise inappropriate, since 
the avocado belongs to the laurel family, while the pear belongs to the 
rose family. How such a barbarism as "alligator pear" could have 
been perpetrated upon this salad fruit it is difficult to imagine. The 
namci avocado is shoi't, concise, and has the advantage of being largel}' 
used b}^ the American growers of this fruit. 

« Catalogus Phuitariim (juac in Insula Jamaica Si)onte l*roveniunt, Pars Prima, 
London, KM), p. 185. 

/^ISIartius, Flora Brasilieusis, Vol. V, ])t. 2, fas(;.41, p. 159. 

^•Transactions, 1902, p. 20. 

'fVroc, Am. Pom. Soc, 190], Part JI, p. 59. 



LITERATURE. 



Mr. C. P. Taft^' says of the avocado in California: 

The avocado, or alligator pear, is destined to receive more and more attention as it 
becomes better known. It is fairly hardy, and a good grower and bearer. Importa- 
tions from Mexico are frequent in the Los Angeles markets, where they sell for fancy 
prices. 

Mr. A. A. Boggs^ says: 

The avocado or alligator pear (Persea gratissima) is already growing rapidly in 
favor in a few of the larger cities where people are beginning to learn its superior 
excellence as a salad fruit, and it bids fair to become an important market crop. It 
has, however, been grown entirely from seed, and as it varies widely in size and 
quality, there is urgent need of improvement in method of propagation. All efforts 
to bud or graft have hitherto proved abortive. The Department of Agriculture made 
an importation of seed of a Mexican variety about three years ago. Some trees from 
these have already come into bearing, and proved a disappointment. The fruit is 
entirely too small and the flavor certainly not superior to the average of the old type. 

Mr. Byron O. Clark says of this fruit in Hawaii: 

The avocado or alligator pear is the one fruit which captures the palate of the vis- 
itor to the Tropics more firmly than any other, provided he acquires a liking for this 
fruit. With the richness and consistency of butter, and a flavor of nuts, it is 
undoubtedly one of the most popular fruits, if not the most popular with residents, 
and acquires such popularity with persons who visit the islands that a good market 
for shipment to the coast is open at any time the fruit can be had. Like almost all 
other kinds of fruit here, the home market is not nearly supplied, and the prices are 
so high that none but the wealthy can use them, except as a luxury. 

LITERATURE. 

Very little has been written about the propagation of the avocado. 
It was introduced into Europe as early as the seventeenth century, but 
has not yet been generally disseminated. Simmonds's ''Tropical Agri- 
culture" does not mention it at all. Woodrow's '^Gardening in 
India," published in 1899, does not refer to it. 

Dr. F. Franceschi ^ speaks of its having fruited in southern Califor- 
nia. He also points out that the demand for it in the larger cities of 
the United States is greater than the supj^ly. 

In 1899 Capt. John J. Haden^*^ exhibited fruit of the avocado in 
Philadelphia. 

The Botanical Register of 18^^9 published a colored plate of this fruit 
(No. 1258), and referred to it as having ])een introduced from the con- 
tinent [America], and as one of the rarest species cultivated in the 
greenhouses. 

Curtis's Botanical Magazine for Ma}^ 1, 1851, published a colored 
plate of an avocado presenting rather an unusijal combination. The 

«Proc., Am. Pom. Soc, 1901, p. 92.. 
&Proc., Am. Pom. Soc, 1901, p. 88. 
cproc. Am. Pom. Soc, 1897, p. 100. 
t^Proc, Am. Pom. Soc, 1899, p. 88. 



12 



THE AVOCADO IN FLORIDA. 



fig'ures of the branches, including the leaA^es and inflorescence, are 
iindouhtedly the West Indian-South American form. The size of the 
fruit is that of the West Indian-South American form, while the color 
of the skin is exactly that of the Mexican avocado. This publication 
also suggests that ^'it is increased ])y cuttings, treated in the usual 
mann.cr.-' So far as the writer's ex})erience goes, the cuttings are diffi- 
cult to strike without l)ottom heat. 

In the Yearl)oolv of the Ignited States Department of Agriculture 
for 1901, page 354:, Mr. O. F. Cook refers to the avocado as one of the 
important fruits of Porto Rico, and sa3^s: 

The alligator pear, also called hutter pear, aguacate, and avocate, is a tropical fruit 
now relatively little known, l)ut with every prospect of a gradually increasing 
popularity. It is a pear only in shaj^e, and might ])etter be compared to the olive, 
because it serves as a salad or a relish rather than a fruit in the ordinary sense, and 
frequently becomes a favorite, even with those who do not like it at first. The flesh 
has a delicate buttery consistency, and is eaten with vinegar, salt, and other condi- 
ments, or is used as an ingredient of other salad compounds. The promise of agri- 
cultural and commercial importance for this fruit lies in the fact that it already has 
a distinct, if limited, place in the markets of our larger cities at from 30 to 60 cents 
apiece, prices which might be halved or quartered and still leave good profits for 
both grower and dealer. ]Moreover, even at these large i^rices the sui3ply of first- 
class fruit seems to be unequal to the demand. 

The alligator pear is perha2;)S the one fruit wlhch Porto Rico is ready to send to 
market in considerable quantity and of prime quality. The tree is easily propa- 
gated from seed, is a vigorous grower, and a free bearer, and there is no apparent 
reason why the alligator pear may not become almost as cheap and nearly as poi)u- 
lar as the orange. 

In the Report of the Florida State Horticultural Societ}^ for 1902, 
Mr. Boggs sa3's: 

Of equal x)i'omise and of greater present market importance is tlie avocado pear, 
whicli is to-day the most costly fruit on the American inarket, and is making more 
frieiids every season. The importance of budding and grafting as ap])lied to this 
fruit is greater tlian the securing of l)etter varieties from al)road, for Florida now 
produces the l)est in tlie world, but in eliminating the inferior sorts which form a 
large i)roi)ortion of seedling oi-ehards and in regulating by selection the season of 
fruitage. There are now tr.>es in Dade County which ripen fruit as early as July 15 
and others as late as Jannary 15. The siti'nilieance of this fact needs no comment. 

Choice avocados i-etailed last season at from ;J5 cents to 75 cents each in the cities, 
and the demand seems to (.ntgrow the sni»i)ly. It is urged that this society, in its 
catalogue, should enconiage the use- of the name avocado, both on the score of cor- 
rectness and of euphony, in place of the absurd misnomer " alligator pear," which 
leads to many mistakes. 

Mr. W. A. Marsh also makes reference to this fruit in the Report 
of tlu^ Florida State Ilorticultural Society for 181>6, as follows: 

Tiie alligator or avocado pear {Permi r/rafissima) is one of the most highly prized 
of all troi)ical fruits. It ])elongs to the order of Lauracefe. The fruit is sometimes 
round, also pear-shaped, containing one large seed about the size and shape of a 
hulled waliHit. The fruit when matuie varies in color from a bright green to a deep 
rich brown, sc^metimes mottled with both colors. Its fiesii is a vegetable inarrow, 



DISTRIBUTION AND TIME OF BLOOMING. 



13 



sometimes called midshipman's Imtter, ami held in various de,i?rees of appreciation 
by different persons. It is also nsed as a salad, being dressed with jx'pper, salt, and 
vinegar, in uhich style it is relished l)y most people. The tree is (.f stately growth, 
often reacliing the height of 40 or 50 feet in Florida, it is an American fruit; it was 
introduced into the gai'dens of S])ain in KiOl, and into the Sunda Isles about the 
middle of the eighteenth century. At the beginning of the eigliteentli century tliis 
tree did not exist in tiie gardens of British India. In America its actual area in a 
wild state is of nnconnnon extent. It has been found in the forests, on the banks of 
rivers, and on the seashore from IMexico and the West Indies to the Amazon. At 
the time of the discovery of America it was found both wild and cuUivated in Mexico. 
According to Hernandez it was cultivated by the people of Peru under the name of 
"palto," but there is no proof that it was wild in that country. 

Mr. W. Harris refers to it in Baile3^'s Cyclopedia of American Hor- 
ticulture as follows: 

The avocado or alligator pear is a native of the West Indies, Mexico to Pern, and 
Brazil. It is very connnon in Jamaica, being found in every settlement or planta- 
tion. The tree grows to a height of 25 to 30 feet. It has ellii)tical or ellii»tical- 
oblong leaves, 4 to 7 inches long, glabrate and pale beneath. The fruits are large, 
more or less pear-shaped, and covered with a green or deei) purple skin and con- 
taining a large quantity of a firm yellowish-green pulp, inclosing a single large seed. 
This fruit is highly esteemed by all classes in the West Indies. The pulp is marrow- 
like, and is eaten as a salad, usually Avith the addition of pepper, salt, and vinegai-. 
Europeans as a rule do not like the fruit at first, but once the taste is acquired they 
become exceedingly, often excessively, fond of it. The pulp contains an abundance 
of oil, which may be used for illuminating purposes; also for soap making. The seeds 
yield a deep, indelible black stain, and are used for marking linen. Plants are 
easily raised from seeds, and in good soil in warm situations they grow rapidly and 
begin to fruit when about 5 years old. There are a good many varieties, differing 
from each other in size, shape, and quality of fruit. These differences are not due 
to careful cultivation and selection in all cases, however, but to natural variation and 
accidental intercrossing. 

DISTRIBUTION AND TIME OF BLOOMING. 

Meissner gives the habitat of the avocado as ''the forest, especially 
on the seacoast and following the rivers of tropical America, as well 
as in jNlexico, Peru, Colombia, Guiana, and the islands of the Antilles, 
thence to subtropical localities where this agreeable fruit is cultivated. 
It is found in Brazil, about Peru, and elsewhere; also about Yuri- 
magnus, in Peru, and in English Guiana.'' 

Emile Rodigas^ thinks that the avocado is native to Brazil. He 
figures a large green fruit without a seed cavit}^ It is interesting to 
note that according to this author it was introduced in France in 1750. 

An herbarium specimen in the New York Botanical Garden, col- 
lected by Mr. H. H. Smith, in Colombia, is accompanied by a note 
stating that the species has exery appearance of being native to the 
mountain forest at an altitude of from 1,500 to 2,500 feet. The time 



« Translation from ]Martius, Flora Brasiliensis, Vol. Y, Part II, p. 159. 
& L' Illustrations Horticole, XXXVI: 15 (1889). 



14 



THE AVOCADO IN FLORIDA. 



of blooming' is given a.s from December to April. The specimen is in 
full bloom and bears the date of December Y, 1898. 

Dr. William Trelease, Director of the Missouri Botanical Gardens, 
who has made repeated excursions to Mexico in connection with the 
study of agaves, informs the writer that the smaller avocado with the 
bluish or l)lackish fruit (the Mexican avocado) is most commonly 
found in the markets on the eastern side of the countr}^, while the 
larger forms occur on the western slope. 

Specimens in the herbarium of the New York Botanical Garden and 
in the United States National jNIuseum indicate that the aA'ocado has 
been widely disseminated. Among those occurring in the herbarium 
of the New York Botanical Garden are some collected at the following- 
places and on the dates given, which are of special interest: Colombia, 
December 7, 1898; Nassau, N. P., March 12, 1903; Key Largo, Fla., 
March 26-29, 1898; island of Saint Croix, March 4, 1896; Porto Rico, 
March 8, 1899; Porotonga, Cook Islands. June, 1^899; Montere}^, Mexico, 
Januar}^ 10, 1828; San Luis Potosi, Mexico, 1879; Nicols Town, 
Andros (Bahamas), March 24, 1890; St. Vincent, British AYest Indies, 
April, 1890; Java, 1865; Jamaica, 1827. The following specimens 
were found among those in the herbarium of the United States' National 
Museum: Martinique, 1871; Danish West Indies, March 4, 1896; 
Santo Domingo, March, 1871; Colima, Mexico, March, 1841. 

The foregoing fifteen localities from Avhich specimens of this species 
have been collected show how widely it has been distilbuted. The 
fact that specimens were collected in ftava as earh' as 1865 shows that 
the plants had been imported a considcral)le time previous to that date. 
While no specimens from the Hawaiian Islands were found in the 
herbaria referred to, it is well known that the species occurs there in 
large quantities. It is also said to occur in the Se^'chelles Islands and 
in Madagascar, and it. is doubtless found in all other tropical islands, 
and to some extent on the seaboard of almost all tropical countries. 

The herbarium specimens referred to give some interesting informa- 
tion regarding the time of blooming. Those collected in Colombia 
show a date of blooming of December and January, while a note upon 
one of the herbarium sheets indicates that the time of Ijlooming extends 
from December to April. In jNlexico the period of blooming seems to 
be about the same as in Colombia. In the West Indies, except the 
Bahamas, the earliest bloom ma}^ occur as early as February, l)ut the 
season of bloom closes in April. In the Bahamas and Florida the 
flowers usually appear al)out the first of Marcli, though sometimes 
blooms occur as (;arly as February, while the blooming period closes 
in April. 

The season near th(^ ecjuator appears to l)e lengthened into five 
months. A shortening of the ])criod of blooming seems to have 



METHODS OF STARTING AN ORCHARD. 



15 



occurred hy crowdino- the entire period into the las two inonths wlien 
the species is taken to the northern limit of its zone. Some allowance 
must be made for variations that occur from year to year, but this does 
not amount to more than two or three Aveeks in South Florida. The 
commercial importance of having this fruit come into the market as 
late in the season as possible and in considerable quantity can not be 
overestimated. 

THE AVOCADO FOR WIND-BREAKS AND SHADE TREES. 

Nearly every orchardist is confronted with the necessity of securing 
good shade tiees al)out his |)renuses, and especially a screen for out- 
buildings and for servants" houses. In addition to shade the question 
of wind-breaks is of great importance where high winds are almost 
certain to occur e^'erv year. The vigorous-growing varieties of avoca- 
dos meet these needs as satisfactorily as the purely ornamental trees, 
and in addition may be expected to give a return of fruit. The fact 
that the avocado can urilize almost anv kind of organic fertilizer with- 
out becoming diseased makes it much more desirable for these pur- 
poses than mangoes and citrous trees. The tall, sturdv growth makes 
free pruning of the lower limbs possible, so as to permit the passage 
of persons and animals under the trees, while the abundant growth of 
leaves will still produce a dense shade. 

METHODS OF STARTING AN ORCHARD. 

The general method of securing an orchard of avocados in Florida is 
to germinate seed in a quart or a two-quart tin can, and after the seed- 
ling has attained the height of a foot or two the can with its contents 
is transferred to the iield where the tree is to grow. A still more 
primitive way of starting an orchard is to plant the seed in the soil 
where the tree is to stand. There is no great difficulty in starting an 
orchard in either way. since ~the largest seeds (iig. 1) weigh several 
ounces and have great vitality. If it does not happen to Ixx'ome in- 
fected by some germs of decay the seed may lie in the soil for an entire 
3'ear awaiting a time favorable for germination. The uuusual amount 
of nourishment stored up in the seed enables the seedling to make 
repeated starts after being dried' off. It is capable of renewing its 
roots several times, as well as its top. 

This method of starting an orchard is quite certain and inexpensive. 
When the trees are one or two years old they may be budded to any 
desired variety. While this is better than to await the uncertain 
results and certain disappointment of a seedling orchard, yet top- 
working is expensive, and if budded trees of known varietv can be 
obtained from a good nursery the}' will be found cheaper in the end 
and much more satisfactory. 



IG 



THE AVOCADO IN FLORIDA o 



THE SEED BED. 



Seed may be obtained in large quantities during the ripening- ^^eason 
from southern Florida, Culja. and other places, in the Antillean region. 

At the present time good seeds cost 
from H to 2 cents each. These prices 
seem somewhat high, but every seed 
is nearly certain to make a seedlino-. 

The seed bed should be made in 
some moist localit}^, in soil free from 
rocks and containing an abundance 
of vegetable matter. The rows may 
be made such distances apart as will 
suit convenience — from 1 to 4 feet. 
Place the seeds from 4 to 6 inches 
apart in a drill 3 or inches deep; 
hrm the soil about the seed and cover 
2 or 3 inches deep. Supph^ a heav}^ 
cover of mulch. 

As soon as the seedlings (see lig. 1) 
appear above grouiid, fertilizer ma}' 
be applied. The mulch should 1)e 
turned back, the fertilizer raked in or 
cultivated in, and the mulch replaced. 
If the seedlings are to be removed 
to the nursery soon, fertilizing and 
cultivating ma}^ be omitted. Removal 
to the nursery mav be deferred until 
seasonable weather. 

THE NUKSEKY. 

For starting a nursery the best 
land should be selected, especiallj^ 
such as is fairly dry though nev(U' 
suffering from drought. Land that 
is subject to flooding should by all 
means be avoided. AVhile the trees 
are able to live in standing water for 
two or three weeks, tliey become su).)- 
ject to attack \)\ Aariuus forms of 
disease. When practicable, a gen- 
erous application of fertilizer should 
be made two or three weeks before 
the trees are set out. It should be 
scattered down the row and raked in, in the usual way. The land should 
be thoroughly grubbed and put into a first-class state of cultivation. 




Fig. 1. — Seedling avocado in December from 
seed planted in September (somewhat t^Xow 
in starting, but otherwise apparently nor- 
mal): (a) First shoot to start: (h) st'coml 
shoot starting from the axil of the iiicii)i('nt 
leaf; (c) third shoot If) start— in v\\<^' of se- 
vere drought or other adverse coudii ions, all 
of tliese shof)ts may fail and some otlu r l)ud 
grow into a new shoot; (cZ) scale-like leaf: {< ) 
one of the cotyledons, the other having been 
removed, sear opposite e; (/) primary root. 
(Iledueed to one-third natural diameter.) 



THE NURSERiT. 



17 



Transplanting to the nursery should be done when the seedlinos are 
6 inches to a foot high. After this time the taproot (see tig. 1,/*) 
will have formed and the transplanting will disturb this and prevent 
it from growing to the large size that it would attain if the seedling 
were not removed. 

For transplanting, rain}^ weather should be chosen; otherwise much 
watering will be necessary or many trees will be lost. From the 
nurseryman's point of view the planting in a seed bed seems unneces- 
savy^ but seeds planted in a nursery produce trees with large taproots 
and few fibrous roots; this is especially the case on land that is more 
or less sandy. 

In th ; nursery the rows should be from 4 to 6 feet apart and the 
trees set about a foot apart in the row. B}^ thorough cultivation and 
generous fertilizing an abundance of fibrous roots will be produced, 
and if tiie nursery is located on moist land most of the trees will pro- 
duce many branched roots and very few large roots. 

CULTIVATION IN THE NURSERY. 

After planting in the nursery, cultivation should be thorougli and 
frequent. The implements should not be permitted to go deeply into 
the soil if it is sandy, but in marl or heavy lands cultivation should be 
as deep as is. practicable. 

BUDDING. 

There have been many and varying reports regarding the possibility 
of budding and grafting the avocado. A few 3'^ears ago it was thought 
impossible to bud it at all. More recently statements have been 
made that 90 to 100 per cent of the buds had ''taken." These reports 
when investigated have been only partially verified, since a large per- 
centage of the buds that take fail to develop. In the avocado there 
seems to be no difficulty in making the buds take, l)ut there is con 
siderable difficulty in making them start. The buds placed in a vigor- 
ous stock are frequently grown over, thus obliterating the bud. Or 
again, the stock on being lopped to induce the bud to start often dies 
back to below the bud. Experience indicates that budding at or near 
the crown is preferable to top-working. 

The difficulty is not with budding but with the want of experience 
up to the present time. The nurserymen do not fully understand the 
time and manner best suited for budding their stock. Some buds 
respond promptly, while others are very dilator}^ about starting and 
may finally fail. 

Shield buds (fig. 2) inserted in the spring w^hen the bark slips well 
and before the first flush, usually take well and make an excellent 
growth. It is very important in the work of budding that the stock 
and scion be in as perfect condition as possible. (See figs. 3 and 1.) 
29619— No. 61—04 2 



18 



THE AVOCADO IN FLORIDA, 



Bud sticks (%. 5) arc cut from well-matured growth, especially such 
as shows an abundance of active l)uds. (See lig. 5, a,) Wood 
with many blind buds (see %. 5, Z», I, V) should be avoided and care 
taken not to use such buds in propagating. Some are likely to occur 
on any stick. 

Various methods of budding have been adopted and some forms of 
grafting have been suggested. The common shield bud (fig. 2) seems 
to be about as successful as any that have been tried, though the patch 
bud is also used with a considerable degree of success. 




Fig. 2.— Shield Fio. 3.— Soed- 



]jud cut out 
prc'purutory 
to insertion-. 



ling iivocado 
stock with 
hhield bud in- 
serted. 





Fig. 4.— Shield 
bud wrapped 
with Avaxed 
cloth. 



(iRAFTING. 



a. 




Fig. 5.— Bud stick; a, «, etc., 
' 'live ' ' buds in various stages 
of dcveloptnent; h, h, etc., 
blind buds which should not 
be used. 



Baltet" recommends four different methods of grafting: (1) Inarch- 
ing, (2) veneer grafting, (3) cleft grafting, and (4) veneer grafting near 
the root. In inarching and cleft grafting the top of the stock is fig- 
ured as having been cut away. In the other two methods the top of 
the stock is left until the scion has started. Well-matured wood will 
live for several weeks if kept in a sufficiently moist condition, and will 
doubtless unite readily with the stock, but it is nmch more wasteful 
of scion wood and a more tedious process than budding. 



''L'Art (le (Jreffer, 7th vd., Var'ia, 1902, p. 22(5. 



TKANSPLANTING. 



19 



TKANSPLANTING TO THE FIELD. 

A great deal of the difficult}^ that has been experienced in trans- 
planting the avocado is due to the fact that most of the trees have been 
grown in "fence corners,'' or possibh^ they have been permitted to 
grow under the tree where the seed fell, thus producing tall, slender 
seedlings, with A^ery few branches and long taproots, but not many 
fibrous roots. A very different result is obtained from trees grown 
in a nurser}^ (see PL III), where, as previously stated, an ai)undance 
of fibrous roots and a good bushy top are produced. A tree of this 
kind transplants without an}^ greater difiiculty than is experienced 
with other orchard trees. 

One hundred budded trees to an acre are sufficient. If the grower 
proposes to have a seedling orchard the trees should be set closer — 
160 to 200 per acre. This should be done with a view to cutting out 
the inferior ones when the}^ come to fruiting. Of the large-growing 
varieties SO trees to the acre will be found sufiicient. If the variety 
is tall and spindle shaped instead of bushy, a larger number may be 
planted. 

In the Antillean region trees grow during the entire year, so there is 
no sensible gradation into winter or anything that corresponds to a 
dormant season, stricth^ speaking. While fruit trees are usualh^ in a 
more or less quiescent state during January- and Februar}^, this con- 
dition is brought about b}^ a diminution in rainfall rather than as the 
result of a reduction in temperature. 

The time to transplant avocados is determined, as in the case of the 
nursery, by the presence of sufficient moisture, and a suitable moist 
period will usually occur in Florida during June, July, or August. 
As the expense of watering during a dr}^ season is much greater than 
the cost of the tree it is cheaper to set the tree out during a rainy 
season. 

A tree should not be transplanted until it has attained a height of 
about 3 feet in the nurser}" (see PI. III). 

In taking up these trees as many of the smaller roots should be 
secured as possible. The roots should be kept moist and the tree Avell 
watered when set out. The top should be cut back to some extent, 
but enough foliage left to shade the stem. ' If the tree is not suffi- 
ciently provided with leaves an artificial shade can be made b}' the use 
of palmetto fans. 

TOP- WORKING TREES. 

Bearing trees ma}^ be top-worked (see PI. II, fig. 2), but it is neces- 
saiw to insert buds on A^igorousl^'-growing sprouts to succeed. If 
there are no sprouts with bright green bark, they may be induced to 
grow by cutting back the branches and thus stimulating some of the 



20 



THE AVOCADO IN FLORIDA. 



latent buds, or })y cLittint>- the trees otf near the ground and then wait- 
ing- for sprouts to start from the crown. Several of these sprouts are 
then budded and the most vigorous of those that have taken are per- 
mitted to grow (see PI. 11, fig. 1). 

CULTIVATION. 

When the trees are set in the field a considerable quantity of mulch 
should be placed about them; this prevents the soil from becoming 
hot about the roots and from drying out. 

In Florida it is better to plant some field crops, such as cowpeas or 
velvet beans, or to sow beggar weed in a 3^oung orchard. During the 
winter, crops of vegetables may be grown in the orchard with advan- 
tage to the trees. The "middles" may be- planted to pineapples, 
since the pineapple fertilizer will produce a good growth of avocado; 
but there is the disadvantage that these plants will dry out the soil 
severely during a drought. During dr}^ weather cultivation should 
be frequent and thorough, but not deep; 3 inches of soil mulch is 
sufiicient to conserve capillary moisture. During the rainy season 
cultivation ma}^ be suspended entirely and the middles planted to 
some cover crop, as indicated above. 

FERTILIZEKS. 

In selecting fertilizers a formula should be chosen in which the 
ammonia is from an organic source, such as dried blood or cotton- 
seed meal, in preference to sulphate of ammonia or nitrate of soda. 
Sulphate of potash will be a safe form to employ as a source of 
potash. It should be used in liberal quantities to insure good firm 
leaves and wood, and also to prevent the dropping of the fruit. 
Phosphoric acid, so far as experiments teach, may be supplied from 
any source that is ordinarily used. If the trees be planted about 
poultry yards, or fowls are allowed to roost in the trees, potash will 
be all the fertilizer needed, ])ut this should be used liberally to keep 
the trees health}^ and free from insect attacks. Such trees when not 
fertilized with potash are usually attacked by insect pests, but as a 
rule are exempt from Gkjeosporium. 

When commercial fertilizers are to be applied, the ordinary "fruit 
and vine" fertilizer, with the ammonia from an organic source, ma}^ 
be used. The quantit}^ required will vary according to the concentra- 
tion of the particular brand, the character of the soil in which the 
trees are growing, and the age of the trees. Fifteen pounds per tree 
per year of fertilizer prepared according to the following formula will 
be found good for growmg trees four or five years old: Ammonia, 5 
per cent; potash, 6 per cent; phosphoric acid, 6 per cent. 



SUPKRIORITY OF BUDDED TREES. 



21 



As the trees g-row older and begin to fruit heaAdly, increase the 
percentage of potash and phosphoric acid. Apply the fertilizer in 
two or three doses during the growing season. The time of applying 
must be determined by the particular orchard under consideration; 
ordinarily an application should not be made during December or Jan- 
uary, as it would be likely to force an early spring growth or even 
cause a vigorous winter growth, which should be avoided. 

If the trees be put into a dormant or semidormant condition during 
December and January, they will make a strong spring growth and 
produce a heavy crop of bloom. If the bloom is retarded as long as 
possible the blooming period will be shortened, and consequently the 
fruit will mature more nearly at one time, thus doing away with the 
necessity of making several pickings from the same tree. 

Trees that have been neglected do not prove productive unless they 
happen to be standing on some place where a large quantity of organic 
matter has accumulated. Trees on abandoned homesteads located in 
the piney woods soon become unproductive and require two or three 
years' nursing to bring them back to good growth and bearing. It 
usually pays better to start in with good, fresh trees from the nursery 
than to attempt to bring out" an abandoned orchard. 

SUPERIORITY OF BUDDED TREES. 

The earlier productiveness of orchards composed of budded and 
grafted trees has been repeatedly demonstrated with most of the tree 
fruits that are grown under cultivation. While occasional seedling 
trees of most species bear at as early an age as the ordinary budded or 
grafted tree of the same species, the trees in a seedling orchard 
usually vary greatly in this particular, and on the average come into 
bearing much later than budded or grafted orchards of varieties of 
the same types of fruits grown under similar conditions. While many 
factors are concerned in producing this result, the greatest advantage 
of budding and grafting is that varieties of known precocity and 
productiveness, as well as other desirable characteristics, can be per- 
petuated with little variation, while the seedling orchard contains indi ' 
viduals differing widely in some or all of these important particulars 

Seedling avocados usually do not fruit until they are four or more 
3^ears old, and they are usually six years old before bearing a crop. 
There are exceptions to this, but the number of seedlings that bear a 
good crop before they are six years old will not amount to 10 per 
cent. 

VARIATION OF FRUIT FROM SEEDLING TREES. 

The S3^stematic work of propagating and cultivating avocados is just 
beginning. The fruit being of American origin, it has come into cul- 
tivation rather recently, and has not had the benefit of centuries of 



22 



THE AVOCADO TN FLORIDA. 



selection and propagation, as is the case with many other orchard 
fruits. Throughout Central America and the West Indies it grows in 
a native state, and only half-hearted attempts are made to put it into 
cultivation. So far as the writer is aware, no orchard of any consid- 
erable size exists outside of Florida. In Cuba, Jamaica, Porto Rico, 
and the Bahamas a few seedling trees are growing around nearly every 
settler's place. The owner plants the seed and takes his chances as to 
the character and fruitfulness of the tree. Under these conditions a 
considerable quantity of fruit is being g-rown and marketed, but the 
product is of an exceedingly variable nature. The two following illus- 
trations prove the truth of this statement. 

DESCRIPTION OF VARIATIONS. 

Mr. G. L. Macdonald, of Cocoanutgrove, Fla., related his expe- 
rience to the writer. In preparing for his orchard Mr. Macdonald 
selected the seed from a tree that bore fruit of exceptionally fine 
quality and in large quantity. At the time the selection was made it 
was generally believed that avocados came true to seed. The parent 
tree produces pear-shaped avocados of large size, fine flavor, and 
purple color, ripening late. The seedling orchard from this tree has 
now come into bearing and produces fruit of variable size and shape; 
good, bad, and indifferent flavor; the color varying from green through 
yellow to purple; and the fruits ripening at different times in the 
season. 

The following census, taken near Buenavista, Fla., in an orchard 
of about an acre in extent, shows how little foundation there is for the 
belief that the avocado trees are unusually fruitful and that the tree 
comes "true to seed." The impression that the tree is unusually 
fruitful doubtless originated from the fact that occasional trees bear a 
heavy crop (see PI. Ill), causing the observer to overlook the dozens 
of trees that have less than ten fruits each or possibl}^ none at all. The 
unfruitfulness and the variability of the product is not more than 
should be expected from an orchard of seedlings. 

This orchard contains IGO trees, 110 of which are five or more years 
of age and of a size to permit the smallest to bear 50 fruits, weigh- 
ing from a pound to one and one-half pounds each. This number of 
trees produced 1,1G1 fruits in 1903, a year during which the avocado 
crop was unusually heav}^ This gave an average of approximately 
10 fruits to the tree. Forty-seven trees bore no fruit at all; -11 trees 
bore from 1 to 12 fruits; 22 bore a crop of more than 12 fruits, 1) of 
these latter trees bearing 595 fruits, or slightly over half the crop. 
The four most prolific trees bore 385 fruits — that is, one-twelfth of 
the trees produced one-third of the fruit, or, stating the matter in 
percentages, 43 per cent of the trees produced no fruit; 37 per cent 



MAKKETING. 



23 



produced 1 to 12 fruits each; 20 per cent produced over 12 fruits 
each. 

Considerino- onl}^ the prolilic trees, we lind that 8 per cent of the 
trees produced 66 per cent and that 3 per cent produced 33 per cent 
of the fruit. 

The nine trees that produced at least a fair crop were of medium 
size, while the hirgest and most vigorous trees in every instance bore 
less than a fair crop. 

Tlie tree- referred to above were from specially selected seed, so 
that it may safely be assumed that they were up to the standard for 
seedling orchards of the same type that have received fair attention 
and are of the same age. Some of the trees that were without fruit 
this 3'ear had a fair crop last year, indicating a tendency on the part 
of the avocado to fruit in alternate 3^ears. The most fruitful trees are 
only moderately vigorous and of a bushy growth. 

Of the 63 trees that have fruited in the orchard mentioned there 
are only 2 which combine good qualities in such a wav as to be 
of special merit. Some trees that bear line fruits are not prolific; 
others ripen their fruit at an inopportune time of the yenv, while still 
others ))ear a fair crop at the right time but the fruit is inferior in 
quality. (See figs. (5, 7. A; 8, and 9.) 

If a census of all the seedling orchards were taken, it is not probable 
that the general results would l)e very different, l)ut this is just what 
should be expected in propagating from seed a species that is so 
variable as the avocado. 

MARKETING. 

PICKING. 

The time of ripening of the avocado extends in Florida from the 
middle of July to December. As now grown, the fruits of a tree do 
not as a rule mature uniformlv, so that in most cases two or more 
pickings have to be made. The variation in this respect is so much 
an individual characteristic that the peculiarities of each tree in the 
case of a seedling orchard, and of each variety if budded, will have to 
be ascertained 1)}^ test. The fruit must be removed from the tree 
while it is still very firm if it is to be shipped to a distant market. 
For local consumption the crop may be permitted to remain on the 
tree mitil a few fruits have fallen. 

In picking, the avocado should be broken off so as to leave a portion 
of the stem attached to the fruit. If a particular variety does not 
break properly, an orange clipper or the ordinar}^ pruning shears may 
be used. If the stem l^e pulled out of the fruit, as occurs in "drops," 
there is a strong probability that some of the fruit will be lost from 
ripe rot in transit, or b}^ softening in the hands of the dealer. 



24 



THE AVOCADO IN FLORIDA. 



GRADING AND SIZING. 



With the avocado, as with all other fancy fruits, it is necessary to 
exercise care to have all the specimens in a crate of uniform shape and 




Fig. G.— Longitudinal sections of round avocados. West Indian-Soutli American varieties (about one- 
half natural diameter i: A. seed rilling the cavity; B, fruit from another tree of better quality, but 
seed loose in the cavity. 




A. . B. 

Fig. 7.— Longitudinal .sections of oblong avocados, West Indian-Soutli American varieties (about one- 
half natural diameter): A, small seed, loose in large cavity; B, large seed, loose in the cavity. 

size. (See figs. 6, 7, 8, and 9.) A few small ones in a crate of otherwise 
large fruits will cause a greater loss to the seller than would have been 



PACKING. 



25 



occasioned by rejecting the small ones. Fruits that average more 
than fifty to a tomato crate are not desirable for sending to distant ' 
markets. While the demand has been so strong that almost an}^ 
avocado in sound condition would sell, too great emphasis can not be 
placed upon the necessity for packing each crate with fruit of uniform 
size, shape, and color. 

While the market has no pronounced demand for any particular 
form, those of a decided pear shape (see fig. 8), of even size, and of 
which about three dozen can ])e packed in a tomato crate, l)ring the 
highest price. 




A. B. 

Fig. 8.— Longitudinal section:; of pear-shaped avocados, West Indian-Sonth American varieties 
(about one-half natural diameter) : A, very large seed, loose in the cavity; B, large seed, loose in the 
cavity. 

PACKING. 

For shipping purposes the market at present demands a tomato 
crate or an eggplant crate. In the course of a few 3"ears a standard 
package of dimensions best adapted to this particular fruit will, no 
doubt, be adopted. Neither the tomato crate nor the eggplant crate 
is perfect from the growers' point of view. The larger package brings 
such a quantity of fruit into one compartment that some of the lower 
ones are likely to be bruised in transit. If some of the avocados hap- 
pen to become soft on the w^ay, the appearance of the remainder will 
be much injured and the selling value of the entire crate will be greatly 
reduced. The tomato crate is much better in these respects, but it is 
not entirely satisfactory, because only the round fruits pack well in it. 



26 



THE AVOCADO IN FLORIDA. 



When the ideal crate shall he adopted it will probably be similar in 
shape to the boxes used for California pears. 

Before packing, the individual avocado should be wrapped in some 
substantial and attractive paper. This will add materiall}^ to the car- 
r3nng quality and to the selling- price of the fruit. Enough fruit 
should be put into the crate so that it will be packed firmly, to pre- 
vent any possibilit}^ of shaking on the way to market. It is not always 




Fig 9 — Loiigitiulinnl scctionsof iMitllc-nofked avocados (ubout one-half natural diameter): A, West 
Indian-South Auiericau variety, witli very large cavity; B, Mexican variety, with seed Idling 
cavity. 



possible to properly fill the crates now used, and it sometimes becomes 
necessary to fill up the vacant space with excelsior. In large crates 
and with well-matured fruit a considerable (juantity of excelsior must 
be used to make sure that the fruit will not be bruised. The produc- 
tion of avocados in the United States is so limited and the demand 
thus far is so much greater than the supply that comparatively little 
care has been necessaiy to secure good prices, provided the fruit 
reached the market in sound condition. 



THE FRUIT. 



27 



THE FRUIT. 

The avocado varies greatly as to size, shape, color, texture, and com- 
position, while the trees also present distinct differences. In size, the 
fruits vary from those no larger than a hen's egg to specimens which 
weigh 3 pounds. (See fig. 7, A, and fig. 9, B.) As to shape, there are 
four recognized types, although all possible gradations occur. The so- 
called round fruit (see fig. 6) is not strictly spherical, being flattened 
at the distal end or at both ends. The oblong fruit (see fig. 7) may be 
of various lengths, but the diameter is always greatest from the stem 
to the distal end. The pear-shaped (see fig. 8) and bottle-necked 
varieties (see fig. 9) are sufficiently descril)ed hy their names. 

The color of a ripe avocado varies from a dark purple, like that of 
a ripe eggplant, to scarlet, yellow, and grass-green. As" a rule, the 
fruit is not of one color over all of its surface; the purple or scarlet 
fruits are usually lighter and the green fruit tinged with yellow at 
the distal end. All combinations of the sizes, colors, and shapes men- 
tioned are found. 

THE EDIBLE PORTION. 

The edible portion of the fruit, called the meat, in desirable varie- 
ties is a smooth, rich substance, with the texture of cream cheese. 
Some inferior fruits are decidedly watery and oil}^ in appearance, while 
others are comparativeh^ dry. 

The following analyses were made hy Charles D. Woods and L. D. 
Merrill. ^' The pulp of three fruits was taken for an analysis. 





Grams. 


Percent. 


Edible portion 


762. 2 
201. 4 
94.0 


71.09 
19.71 
9.20 


Seeds 


Skins 


Total 


1,021.6 


100. 00 





o Thirty-six ounces. 



It was found that 1 pound of the edible portion contained the fol- 
lowing weights of nutrients: 

Pound. 



Water 0. 811 

Protein 010 

Fat , 102 

Carbohydrates . 068 

Ash 009 



The fuel value is estimated at 1,758 calories per pound of edible 
portion. 



« Maine Agr. -Exp. Sta. Bui. 75, July, 1901, p. 111. 



28 



THE AVOCADO IN FLORIDA. 



In color of meat the fruits of different varieties vary. Immediately 
under the epidermis it is green, sometimes for only a fraction of an 
inch; in other varieties it may be green three-quarters of the way 
through the meat, the remainder being either whitish or yellowish, 
or the green color may extend almost to the seed. Some of the 
finest varieties have a cream-colored meat. In texture some av^ocados 
have rather watery meat, with a number of strings running through 
it, and are decidedly inferior to fruit with firm meat and no strings. 

SP]ED AND SEED CAVITY. 

The variations in the seed cavity are of importance from a commer- 
cial standpoint. In some fruits the seed is lodged firmly in the meat; 
in others it occupies only a fraction of the cavity (compare figs. 6, 7, 
8, and 9), and variations occur an}^ where between these extremes. 
Obviousl}^, the best shipping fruit is that with a seed cavity so small 
that the seed can not be shaken about, since in handling the fruit in 
transit the seed in a large cavity so bruises the meat as to cause rapid 
deterioration. This point should be borne in mind in selecting varie- 
ties for propagation. 

In the shape and size of the seed marked variation occurs. The 
shape does not necessaril}^ conform to that of the fruit, while the size 
may vary from one-half the bulk of the fruit down to one-tenth or 
even less. (Compare figs. 6, T, 8, and 9.) One tree that bears seedless 
fruit has been discovered in Florida. Since the formation of seeds is 
the greatest tax on the energies of the plant, it is important for the 
grower to produce fruits with as small seeds as possible; these the 
buyer will also prefer, as to him the seed is of no value. 

SHAPE OF THE TREE. 

The manner of growth of avocado trees differs exceedingl3\ Some 
trees grow with a slender shape, like the Lombardy poplar; others 
spread out in the form of an American elm, while the greater number 
take on the compact shape of a fruit-bearing tree, making an outline 
somewhat similar to that of a haj^cock. (Compare Pis. I, II, and III.) 
This last mentioned form is, of course, the most desirable of the dif- 
erent shapes. It gives the tree a chance to withstand gales, smd per- 
mits the fruit to sway on slender branches, thus keeping it from 
being blown off" during storms. 

FORMS AND VARIETIES. 

The sp(M'io- J\ r.sea (j?'(di'isir//a Giirtn. ^ ov what is popularlv known as 
avocado, is \\(;ll defined from the other species of the genus, but 
inside of the species as at present understood it is exceedingly vari- 
al)le. Some attempt has been mndc to separate this species into vari- 
eties, but so little has yet been done in the way of perpetuating 



FORMS AND YARIP]TIES. 



29 



particular sorts by bud propagation that varieties in the pomological 
sense have not yet found a place in literature. La Sagra" gives the 
following classitication, based upon the characters of the fruit: 

The aguarate is, without doubt, one of the most valuable fruit trees of South 
America. The fruit is in form of a large pear, without any depression at the head. 

The skin is a yellowish green or a pale violet color, and smooth. The snl)stance 
of the fruit, when well matured, is nearly white and lias a soft, oily consistency 
ami a slightly sweet taste, somewhat sugary. It is eaten in its natural state and also 
seasoned in various manners, nearly always with a little salt. The animals devour 
it eagerly. 

The tree blossoms in April and the fruit matures in July and August. The varie-. 
ties which are cultivated in Cuba are — 

1. The violet color, which is nearly round in shape. 

2. The large green, round, with the inside yellowish and having the consistency 
of bread. 

3. The large yellow, similar to a large pear. 

4. The long green. 

The maturity of the fruit is known ^vhen the seed which it contains becomes 
loosened from the substance of the fruit and rattles when it is shaken. 

In order to obtain good trees one nuist sow the seed in the place where it will 
remain permanent, in holes of 3 feet in dimension in every direction, which are 
tilled with good soil. 

These trees ordinarily bear fruit from the fifth year and live to about their 
eightieth year. They are planted in form of beautiful groves and walks about the 
dwellings of the inhabitants, and as their growth is very vigorous they soon take 
strength from neighboring trees. Their flowers yield a very agreeable perfume. 

Compare the description of plates, page 36, and tigs. 6, 7, 8, and 9 
with the above description. 

Meissner^ recognizes several l)otanical varieties based upon the 
shape and size of the leaves. Vuh/aris has leaves ''3-4 polF' by 
"li polir OUouija, ^-4-0 poir' by' f-2 poll;" Macrophylla, "6-9 
poll" by ''3Mt poll." 

THE MEXICAN AVOCADO. 

There is a small-fruited form of avocado which was introduced in 
1893 from Mexico (see hg. 9, B) in the form of seeds by the Divi- 
sion of Pomology of the Department of Agriculture, to which no ref- 
erence is made in the literature examined, and no specimens of this 
form were found in the herbaria visited. It is regarded in iVIexico 
as more frost resistant than the common form found in Florida and 
the AVest Indies, but is not considered as valuable as the larger fruited 
varieties where the latter may be grown successfullv- Its fruit is 
pear-shaped, or bottle-necked, about the size of a hen's egg, usually 
of a dull blackish or bluish color. The skin of the fruit is thin and 
leathery. The seed is small, conical, usuallv about an inch in diameter. 

"Translation from Historia Fisica de Cuba (1845), Vol. XI, p. 186. 

^ Correct for some varieties only. — P. H. R. 

<^ Martins, Flora Brasiliensis, Vol. V, f)t. 2, fasc. 41, p. 159. 



30 



THE AVOCADO IN FLORIDA. 



The tree is a less vioorous grower, and the branches are inclined to be 
slender. The leaves are borne on a slender petiole about half as long 
as the blade, which is thin and elliptical in shape. Tlie flowers are 
borne in an open panicle on long slender pedicels and the fruit ripens 
earlier than the West Indian-South American form. 

Another striking peculiarity of this form is that the first pair of 
scale-like leaves produced have, while those of the West Indian-South 
American form do not have, a distinct petiole and blade. (See flg. 1.) 
This form has been grown successfully in California, where it is 
becoming popular. Figure 9, B, is from a specimen kindly furnished 
by Mr. W. Chappelow, Monrovia, Cal., from a tree grown from seed 
of the first importation from Mexico b}^ the Department of Agriculture. 

THE WEST INDIAN-SOUTH AMERICAN AVOCADO. 

The fruit of the West Indian-South American avocado is large, 
varjang in weight from a quarter of a pound to 3 pounds. The shape 
is as varial)le ,as the size, varying from oblate spheroidal to almost 
banana shaped. (See figs. 6, 7, 8, and fig. 9, A.) The color of the fruit 
is purple, scarlet, j^ellow, and green. The rind is usually thick and 
brittle. The seed is often very large, sometimes making up one-half 
the weight of the fruit; the shape of the fruit variable — spheroidal to 
conical. The tree is of vigorous growth, reaching a height of 20 to 
30 feet, and sometimes is even taller; the branches are thick and brittle. 
The leaves are borne on a short, thick petiole, less than one-fourth the 
length of the blade, which is thick, elliptical, and from 4 to 10 inches 
long. The lower surface of young leaves is covered with a pubescence. 
Flowers in open panicle are borne on a short peduncle. The fruit is 
borne on a thick pedicel, and ripens from the middle of July to Decem- 
ber. A few trees retain their fruits until Januar}^, and even up to 
March. 

In the native habitats the species seem to run to distinct forms, 
as is indicated from the botanical literature and botanical specimens 
named by authorities on the subject. These forms do hot come true 
to seed when l)rought into cultivation, owing probabl}^ to the fact that 
the trees are put under special new conditions, and that trees from a 
large imm])er of varieties are planted near to each other, making cross- 
P')Hination almost certain. It is not surprising, therefore, that we 
hnd large-fruited and small-fruited trees; yellow, green, scarlet, and 
purple colored fruit; small, medium-sized, and large leaves; good, 
bad, and indiflerent qualities, all coming from selected fruits from a 
singhi tree, as indicated from observations cited on a former page. 
It is really only what should l)e expected when viewed from a plant 
bre(Hler\s standpoint. 



FORMS AND VARIETIES. 



81 



THE IDEAL AVOCADO. 

The tree should be of small or medium size. So long as the supply 
is limited and the fruit brings fancy prices, the cost of gathering from 
the tall-growing trees is no serious obstacle, but much fruit is lost 
from a tall tree as a result of high winds, which are common in the 
Antillean region during the ripening season. 

The fruit should weigh about a pound to a pound and a half. This 
is large enough for persons with an ordinary liking for this fruit, 
while those who are extraordinarily fond of it can call for two fruits. 
Pear-shaped (see fig. 8) or oblong varieties (see fig. Y) should be pre- 
ferred, as they can be packed readily and transported without much 
danger of being bruised in transit. The seed should not be loose in 
the cavity, as the shaking of it in transit pounds the meat into an 
unsightly mush. The color of the fruit should be either yellow or 
scarlet. The fruits that ripen green are considered by the novice as 
having been picked when too immature, and those that ripen brown 
or purple look as if they w^ere in the first stages of decay. A very 
late variety would undoubtedly be the most desirable, since it would 
ripen at a time when all the West Indian and Mexican avocados were 
gone, and most of the northern fruits were out of the market. 

USES OF THE FRUIT. 

According to Patrick Brown, horses, cows, cats, dogs, as well as all 
sorts of birds, feed on this fruit. 

Much hfis been written regarding the manner of serving this salad 
fruit, but only one or two essential additions have been made in the 
last two hundred years. No matter how daintil}^ it may be prepared 
one can scarcely relish it more than when, tramping through the 
forests, he happens upon a tree with a few fruits fully matured. The 
traveler, is likely to be seated at once, enjoy his fruit without salt, 
sugar, or other condiments, and forever after he will remember the 
deliciousness of that particular fruit, which if eaten with any or all 
condiments at the most carefully appointed table would not have made 
as strong an impression on his memor3^ 

An avocado should not be used until the meat cuts smoothly with a 
teaspoon and is about the consistency of well-frozen ice cream. No 
one should attempt to eat the fruit after it has softened; a rancid 
avocado may well be compared to rancid butter. 

The simplest way of using this fruit is as already stated. One 
merely halves the fruit, removes the seed, and dips out the meat with 
a teaspoon, or to the plain fruit a bit of salt ma}^ be added. Some 
people use pepper in addition. The number of waj-s in which the 



« Civil and Natural History of Jamaica, London, 1789, p. 214. 



32 



THK AVOCADO IN FLORIDA- 



avocado may be .served is as varied as the possible salad eouibinations. 
One should not, however, deliio-e this rich fruit with oil nor overpower 
with condiments its mild, nutty Havor. Salt, pepper, and vinegar are 
often used; if to this enough sugar ))e added to take off the sharpness 
of the vinegar, it will be an impro\'einent. Lime juice or lemon juice 
mav ))e substituted for the vinegar with advantage. The avocado is 
sometimes served as a dessert with sugar and sherr}' . 

Another distinct method of using this fruit is to remove the meat 
from the skin, add the condiments desired, and theii stir the w-hole 
into the form of a salad and serve either alone or on lettuce leaves. 
Some chefs cut the meat into small cubes of about a half or one-third 
of an inch in si/e and serve it with condiments, as in minced salad. 

The use of the avocado as an ingredient of lobster or other shelltish 
salad is said to have become (piite general in lociilities wdierc the fruit 
can be obtained, as it gives the salad a pleasing nutty after flavor not 
otherwise secured. 

Another use is in mixed pickles. For this purpose the fruit should 
be selected before it has become soft, yet after it is no longer hard and 
brittle. The fruit is pared, the seed taken out, and the meat cut into 
pieces not over a half inch thick. This is then prepared in the U!?ual 
manner for cucumber pickles, etc. 

DISEASES. 

LEAF DISEASE. 

While the avocado has recently been introduced into cultivation, it 
has some severe diseases, which, however, can be handled without 
nuich dilHcult}' if taken in time. One of the most prominent and 
common diseases noticed is due to a Ghi'osjxn'ni m ^ prol)ably an unde- 
scrilx'd s[)ecies. This almost invariably attacks the leaf at the tip, 
and gradually works ))ack from this point into the blade. By the time 
the h'iif has become two-thirds or three-cpiarters diseased, it usually 
falls otf, and in this way the fungus may defoliate the entire tree. 

lu'iiirih/. — S[)raying with Hordeaux mixture" should be begun on 
the lirst appearance of the trouble. If spraying is delayed until tiie 
tree has been partially defoliated, success will be attained with much 
greater difliculty. 

"Bordeaux inixtuic iiki\ he pri-parcd hy disHolving 6 pounds of l)luest()nc in 25 
fjallons of water. This may be done readily by j)lacing the ])hiefstone in a feed sack 
and sn.^peniling it near the; surface of tiie water. Slake (5 pound.s of Hnie with just 
enou^ih water to cover it. When this lias been thoroufrhly slaked, dilute with 25 gal- 
hjn.sof water. Strain the slakecl lime into the tank of the spraying machine through 
coarise sacking, to remove all jtarticles which might cl<»g the spraying machine. INiur 
the dissolved hluestone into the lime water, stirring vigorously for two or thit-e min- 
utes. Apply at (»nce. 



SUMMARY. 



33 



FRUIT DISEASE. 

Apparently the same fungus which causes the disease of the leaves 
attacks the fruit in various stages of development. If the disease 
becomes prevalent while the fruit is small, it will shed o& until the 
tree is quite fruitless. If the disease attacks the more mature fruit, 
it is liable to remain on the tree until nearly ripe, but the fungus pro- 
duces a brown spot, and linally the skin cracks. 

Itemed I/. — The same remedy should be used as for the leaf fungus. 

SUMMARY. 

Avocados do not come true to seed. 

Orchards of seedling trees can not l)e relied upon to produce go jd 
crops. 

Budding is practicable and it is the most desirable way of propa- 
gating. 

Crown-working is preferable to top-working. 

Budded trees grown in a nursery should be used in planting an 
orchard. 

All the fruit shipped to market in a crate should be of the same 
size, of the same shape, and of one color. 

Preferences for color are as follows: Yellow, scarlet, green, brown. 

Pear-shaped fruits and oblong shapes are preferred. Round are 
less desirable than bottle-necked fruits. 

The varieties which ripen during December, or later, sell for the 
highest prices. 

The large percentage of fat contained in this fruit makes it especialh^ 
desirable, since it is much more agreeable to some people than the fat 
obtained from a:i animal source. 

29619— No. 61—04 3 



PLATES 



35 



DESCRIPTION OF PLATES. 

Plate I. Frontispiece. — West Indian-South American avocado tree, about 35 years 
old, growing on a coral breccia reef. Produces fruits of fine quality. Ripens 
purple. 

Plate II. Fig. 1. — Crown-worked avocado tree eighteen months after insertion of 
bud. The bud was placed in a sprout that had started from a stump of a tree 
the summer before. West Indian-South American variety. About 8 feet tall. 
Fig. 2. — Top-worked tree eighteen months after insertion of bud, which was 
placed in a green sprout. The tree was approximately of the same age and vigor 
as the one shown in Plate II, figure 1. Mexican variety. About 12 feet tall. 
Compare the general mode of growth, arrangement of leaves, etc., with the tree 
shown in Plate II, figure 1. 

Plate III. Nursery tree two years old, transplanted from seed bed, West Indian- 
South American variety. A good, vigorous stock for budding. About 4 feet 
tall. 

Plate IV. Fruiting branch of W^est Indian-South American variety, showing the 
manner in which the fruit is borne upon the branches. The photograph from 
which this illustration was made was taken from the inside of the tree to bring 
out the peculiar mode of attachment. This branch may be considered as carry- 
ing a very heavy crop. Fruits about one-tenth natural diameter, ripening green. 
36 



o 



Bui. 61, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 




Bui. 6\: Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE IV. 



I 

[p. Mr '08 



